#![allow(non_snake_case)] use std::io::{ self, prelude::* }; macro_rules! pick { ($tokens:expr) => { $tokens.next().unwrap().parse().expect("parse error") } } fn powmod(a: i64, b: i64, p: i64) -> i64 { if b == 0 { return 1; } if b == 1 { return a%p; } let (q, r) = (b/2, b%2); let mut res = 1; res *= powmod(a, q, p).pow(2); res %= p; if r == 1 { res *= a; res %= p; } res } fn invmod(a: i64, p: i64) -> i64 { powmod(a, p-2, p) } struct Solver { memo: Vec>, } impl Solver { const MOD: i64 = 1_000_000_007; fn new() -> Self { let mut memo = vec![None; 100001]; memo[1] = Some(1); memo[2] = Some(2); memo[3] = Some(6); Self { memo, } } fn f(&mut self, n: i64) -> i64 { if let Some(res) = self.memo[n as usize] { return res; } let mut res = 0; res += n * self.f(n-2); res %= Solver::MOD; res *= invmod(n-2, Solver::MOD); res += n*self.f(n-1); res %= Solver::MOD; self.memo[n as usize] = Some(res); res } } fn main() { let mut s = String::new(); io::stdin().read_to_string(&mut s).expect("i/o error"); let mut tokens = s.split_whitespace(); let N: i64 = pick!(tokens); let mut solver = Solver::new(); let ans = solver.f(N); println!("{}", ans); }